\begin{tikzpicture}
    \tkzDefPoints{0/0/B, 2.6/0/C, 1.3/3/A}
    \tkzDefMidPoint(B,C)  \tkzGetPoint{D}
    \tkzDefLine[altitude](A,D,B)  \tkzGetPoint{F}
    \tkzDefLine[altitude](A,D,C)  \tkzGetPoint{E}
    \tkzDrawPolygon(A,B,C)
    \tkzDrawSegments(D,E  D,F)
    \tkzMarkRightAngle[size=0.2](D,F,B)
    \tkzMarkRightAngle[size=0.2](D,E,C)
    \tkzLabelPoints[above](A)
    \tkzLabelPoints[left](F)
    \tkzLabelPoints[right](E)
    \tkzLabelPoints[below](B,D,C)
\end{tikzpicture}

